Difference between revisions of "HS-PS1-11"
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| Level1 = Given an investigation plan or provided information, select appropriate tools and/or materials that could be used to identify a property or behavior of an acid or base. | | Level1 = Given an investigation plan or provided information, select appropriate tools and/or materials that could be used to identify a property or behavior of an acid or base. | ||
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| + | == Phenomena == | ||
| + | The NYSED-specific disciplinary core idea for HS-PS1-11 (see [[#NGSS Dimensions|NGSS Dimensions]] below) names the contexts in which acids and bases matter: ''"agricultural applications, environmental impacts (acid rain), animal and plant physiology"'' and the daily lives of humans and other organisms. The question clusters NYSED has released for this performance expectation draw on the same contexts: a blueberry field, the New York fruit industry, pool water, and beverages. | ||
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| + | === Environmental impacts: acid rain in the Adirondacks === | ||
| + | [[File:Big Moose Lake NY USA.jpg|thumb|right|320px|Big Moose Lake in the western Adirondacks, one of the most closely studied acidified lakes in North America. Photo: James H. Dunning, CC BY-SA 2.5, via Wikimedia Commons.]] | ||
| + | Rain is naturally slightly acidic (pH ≈ 5.6) because dissolved carbon dioxide forms carbonic acid. Through the 20th century, sulfur dioxide and nitrogen oxides from coal-burning power plants in the Midwest were carried east on prevailing winds and returned to the ground as sulfuric and nitric acid, making precipitation in the Adirondacks far more acidic than normal. The region's thin soils and granite bedrock contain few carbonate minerals, so its lakes have little capacity to neutralize acid. When the Adirondack Lakes Survey Corporation sampled 1,469 lakes and ponds between 1984 and 1987, roughly a quarter had a pH of 5.0 or below and nearly half had little or no buffering capacity; many had lost their brook trout. Acidic water also leaches aluminum from soil, and dissolved aluminum damages fish gills. The 1990 Clean Air Act Amendments cut sulfur dioxide emissions sharply, and sulfate in Adirondack lakes has been falling since, but pH and acid-neutralizing capacity are recovering slowly and full recovery is expected to take decades. | ||
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| + | === Agricultural applications: growing blueberries and apples === | ||
| + | Most crops grow best in soil that is near neutral, and farmers routinely "lime" fields with crushed limestone to raise the pH of acidic soil, a neutralization reaction carried out on the scale of an entire field. Blueberries are the exception: they need acidic soil, around pH 5.0, and at higher pH they cannot take up iron and their leaves turn yellow. To lower soil pH, growers work elemental sulfur into the soil, where soil bacteria slowly oxidize it to sulfuric acid, or fertilize with ammonium sulfate, which is both a nitrogen source and an acidifier. Because both adjustments take months and are easy to overshoot, soil pH testing is a normal part of managing an orchard or berry field in New York. This is the context behind the ''A Profitable Blueberry Field'' sample cluster and the ''Fruit Industry in New York State'' cluster from August 2026. | ||
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| + | === Animal and plant physiology === | ||
| + | [[File:Blue hydrangea (Dwight Sipler).jpg|thumb|right|320px|Bigleaf hydrangea blooms in shades of blue in acidic soil and pink in neutral or alkaline soil: a living pH indicator. Photo: Dwight Sipler, CC BY 2.0, via Wikimedia Commons.]] | ||
| + | Living things depend on keeping acids and bases in a narrow balance. Human stomach acid is mostly hydrochloric acid at a pH of about 1.5 to 3.5, which activates digestive enzymes and kills most microbes; antacid tablets are weak bases such as calcium carbonate or magnesium hydroxide that neutralize excess acid. Blood, by contrast, is held between pH 7.35 and 7.45 by the bicarbonate buffer system, and a shift of even a few tenths of a pH unit is a medical emergency. Plants respond to the acidity of their surroundings too. Bigleaf hydrangeas are the classic example: in acidic soil, aluminum ions become soluble, the plant absorbs them, and the flowers turn blue; in neutral or alkaline soil the aluminum stays locked up and the same plant blooms pink. Gardeners change the color deliberately by adding aluminum sulfate or garden lime. | ||
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| + | === Daily life: pools and beverages === | ||
| + | Two of the released question clusters for HS-PS1-11 use ordinary consumer settings. In a swimming pool, chlorine dissolves to form hypochlorous acid, which partly ionizes to the hypochlorite ion. The un-ionized hypochlorous acid is the far better disinfectant, and the balance between the two forms depends on pH, so pool operators keep the water in the CDC-recommended range of pH 7.0 to 7.8, lowering it with muriatic (hydrochloric) acid or sodium bisulfate and raising it with sodium carbonate. In beverages, carbonic and phosphoric acid give colas a pH of about 2.5 to 3.5, coffee sits near 5, and milk near 6.7. Tooth enamel begins to dissolve below a pH of about 5.5, which is why dentists worry more about sipping soda all afternoon than about a single glass at dinner. | ||
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== {{Resourcesheading}} == | == {{Resourcesheading}} == | ||
Latest revision as of 10:57, 21 September 2026
Plan and conduct an investigation to compare properties and behaviors of acids and bases.
Clarification statement: Examples of properties could include pH values (concentration), neutralization capability and conductivity. Observations of behaviors could include the effects on indicators, reactions with other substances, and efficacy in performing titrations.
Assessment boundary: Reactions are limited to Arrhenius and Bronsted-Lowry acid-base reactions.
Note: this is a NYSED-specific performance expectation that is different from the Next Generation Science Standards.
Assessment
What assessment of HS-PS1-11 might look like on a NY state exam.
Performance Level Descriptions
PLDs communicate the knowledge and skills expected of students to demonstrate proficiency in each Learning Standard. NYS assessments classify student performance into one of five levels.
Phenomena
The NYSED-specific disciplinary core idea for HS-PS1-11 (see NGSS Dimensions below) names the contexts in which acids and bases matter: "agricultural applications, environmental impacts (acid rain), animal and plant physiology" and the daily lives of humans and other organisms. The question clusters NYSED has released for this performance expectation draw on the same contexts: a blueberry field, the New York fruit industry, pool water, and beverages.
Environmental impacts: acid rain in the Adirondacks
Rain is naturally slightly acidic (pH ≈ 5.6) because dissolved carbon dioxide forms carbonic acid. Through the 20th century, sulfur dioxide and nitrogen oxides from coal-burning power plants in the Midwest were carried east on prevailing winds and returned to the ground as sulfuric and nitric acid, making precipitation in the Adirondacks far more acidic than normal. The region's thin soils and granite bedrock contain few carbonate minerals, so its lakes have little capacity to neutralize acid. When the Adirondack Lakes Survey Corporation sampled 1,469 lakes and ponds between 1984 and 1987, roughly a quarter had a pH of 5.0 or below and nearly half had little or no buffering capacity; many had lost their brook trout. Acidic water also leaches aluminum from soil, and dissolved aluminum damages fish gills. The 1990 Clean Air Act Amendments cut sulfur dioxide emissions sharply, and sulfate in Adirondack lakes has been falling since, but pH and acid-neutralizing capacity are recovering slowly and full recovery is expected to take decades.
Agricultural applications: growing blueberries and apples
Most crops grow best in soil that is near neutral, and farmers routinely "lime" fields with crushed limestone to raise the pH of acidic soil, a neutralization reaction carried out on the scale of an entire field. Blueberries are the exception: they need acidic soil, around pH 5.0, and at higher pH they cannot take up iron and their leaves turn yellow. To lower soil pH, growers work elemental sulfur into the soil, where soil bacteria slowly oxidize it to sulfuric acid, or fertilize with ammonium sulfate, which is both a nitrogen source and an acidifier. Because both adjustments take months and are easy to overshoot, soil pH testing is a normal part of managing an orchard or berry field in New York. This is the context behind the A Profitable Blueberry Field sample cluster and the Fruit Industry in New York State cluster from August 2026.
Animal and plant physiology
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Living things depend on keeping acids and bases in a narrow balance. Human stomach acid is mostly hydrochloric acid at a pH of about 1.5 to 3.5, which activates digestive enzymes and kills most microbes; antacid tablets are weak bases such as calcium carbonate or magnesium hydroxide that neutralize excess acid. Blood, by contrast, is held between pH 7.35 and 7.45 by the bicarbonate buffer system, and a shift of even a few tenths of a pH unit is a medical emergency. Plants respond to the acidity of their surroundings too. Bigleaf hydrangeas are the classic example: in acidic soil, aluminum ions become soluble, the plant absorbs them, and the flowers turn blue; in neutral or alkaline soil the aluminum stays locked up and the same plant blooms pink. Gardeners change the color deliberately by adding aluminum sulfate or garden lime.
Daily life: pools and beverages
Two of the released question clusters for HS-PS1-11 use ordinary consumer settings. In a swimming pool, chlorine dissolves to form hypochlorous acid, which partly ionizes to the hypochlorite ion. The un-ionized hypochlorous acid is the far better disinfectant, and the balance between the two forms depends on pH, so pool operators keep the water in the CDC-recommended range of pH 7.0 to 7.8, lowering it with muriatic (hydrochloric) acid or sodium bisulfate and raising it with sodium carbonate. In beverages, carbonic and phosphoric acid give colas a pH of about 2.5 to 3.5, coffee sits near 5, and milk near 6.7. Tooth enamel begins to dissolve below a pH of about 5.5, which is why dentists worry more about sipping soda all afternoon than about a single glass at dinner.
Resources
Examples and discussion of resources for the learning, teaching, and assessment of HS-PS1-11.
This section could be expanded upon. You can help out by adding to this section.
NGSS Dimensions
Performance expectation HS-PS1-11 was developed using the following elements from the NRC document A Framework for K-12 Science Education:
- Planning and Carrying Out Investigations
- Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design: decide on types, how much, and accuracy of data needed to produce reliable measurements and consider limitations on the precision of the data (e.g., number of trials, cost, risk, time), and refine the design accordingly.
- Select appropriate tools to collect, record, analyze, and evaluate data.
- PS1.B: Chemical Reactions
- (NYSED) Acids and bases play an important role in the daily lives of humans and other organisms (e.g. agricultural applications, environmental impacts (acid rain), animal and plant physiology).
- Patterns
- Different patterns may be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations of phenomena.